I have setup ZCS 8.0.3 server and have taken a backup using zmbkpose which actually uses getRestUrl method to backup the mailboxes. Now to restore the same I need to have a same LDAP which was used at the time of backup.
I also have RSYNC kind of backup done for entire /opt/zimbra directory with ldap database backed with mdb_copy. Now when I uninstall the entire zimbra on my test machine to see if the restore works, I did

Uninstall the previous zimbra
Installed the same version, same domain, same hostname. Installation goes fine
Now I have stopped the services and removed mdb.db which is of 80GB and replaced with the backup copy.

The issue arises when I start the server and services failed to start. Does that mean only taking a backup with mdb_copy would not suffice the need and would not backup the entire LDAP database which will be useful at the time of exigency?

Can some one recommend what method to use to backup LDAP database so that it can be restored with new installation?